<title>距离咨询</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span> <span class="pl-cpf">&lt;cmath&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;cstdio&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;cstring&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;iostream&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;algorithm&gt;</span><span class="pl-cp"></span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>
<span class="pl-k">const</span> <span class="pl-kt">int</span> <span class="pl-n">N</span> <span class="pl-o">=</span> <span class="pl-mi">40005</span><span class="pl-p">;</span>
<span class="pl-k">const</span> <span class="pl-kt">int</span> <span class="pl-n">M</span> <span class="pl-o">=</span> <span class="pl-mi">100005</span><span class="pl-p">;</span>
<span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">,</span> <span class="pl-n">m</span><span class="pl-p">,</span> <span class="pl-n">Log</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">][</span><span class="pl-mi">30</span><span class="pl-p">],</span> <span class="pl-n">d</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">dep</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-n">nxt</span><span class="pl-p">[</span><span class="pl-n">M</span><span class="pl-p">],</span> <span class="pl-n">to</span><span class="pl-p">[</span><span class="pl-n">M</span><span class="pl-p">],</span> <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">M</span><span class="pl-p">],</span> <span class="pl-n">lj</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">cnt</span><span class="pl-p">;</span>
<span class="pl-kt">void</span> <span class="pl-nf">add</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">f</span><span class="pl-p">,</span> <span class="pl-kt">int</span> <span class="pl-n">t</span><span class="pl-p">,</span> <span class="pl-kt">int</span> <span class="pl-n">p</span><span class="pl-p">){</span>
    <span class="pl-n">cnt</span><span class="pl-o">++</span><span class="pl-p">;</span>
    <span class="pl-n">to</span><span class="pl-p">[</span><span class="pl-n">cnt</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">t</span><span class="pl-p">;</span>
    <span class="pl-n">nxt</span><span class="pl-p">[</span><span class="pl-n">cnt</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">lj</span><span class="pl-p">[</span><span class="pl-n">f</span><span class="pl-p">];</span>
    <span class="pl-n">lj</span><span class="pl-p">[</span><span class="pl-n">f</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">cnt</span><span class="pl-p">;</span>
    <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">cnt</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">p</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">void</span> <span class="pl-nf">build</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">x</span><span class="pl-p">){</span>
    <span class="pl-n">dep</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">dep</span><span class="pl-p">[</span><span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">][</span><span class="pl-mi">0</span><span class="pl-p">]]</span> <span class="pl-o">+</span> <span class="pl-mi">1</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-n">lj</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">];</span> <span class="pl-n">i</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-n">nxt</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">])</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">to</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">!=</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">][</span><span class="pl-mi">0</span><span class="pl-p">]){</span>
            <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">to</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]][</span><span class="pl-mi">0</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">x</span><span class="pl-p">;</span>
            <span class="pl-n">d</span><span class="pl-p">[</span><span class="pl-n">to</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]]</span> <span class="pl-o">=</span> <span class="pl-n">d</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">]</span> <span class="pl-o">+</span> <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">];</span>
            <span class="pl-n">build</span><span class="pl-p">(</span><span class="pl-n">to</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]);</span>
        <span class="pl-p">}</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">lca</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">p</span><span class="pl-p">,</span> <span class="pl-kt">int</span> <span class="pl-n">q</span><span class="pl-p">){</span>
    <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">dep</span><span class="pl-p">[</span><span class="pl-n">p</span><span class="pl-p">]</span> <span class="pl-o">&lt;</span> <span class="pl-n">dep</span><span class="pl-p">[</span><span class="pl-n">q</span><span class="pl-p">])</span>
        <span class="pl-n">swap</span><span class="pl-p">(</span><span class="pl-n">p</span><span class="pl-p">,</span> <span class="pl-n">q</span><span class="pl-p">);</span>
    <span class="pl-kt">int</span> <span class="pl-n">d</span> <span class="pl-o">=</span> <span class="pl-n">dep</span><span class="pl-p">[</span><span class="pl-n">p</span><span class="pl-p">]</span> <span class="pl-o">-</span> <span class="pl-n">dep</span><span class="pl-p">[</span><span class="pl-n">q</span><span class="pl-p">];</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-n">Log</span><span class="pl-p">[</span><span class="pl-n">d</span><span class="pl-p">];</span> <span class="pl-n">i</span> <span class="pl-o">&gt;=</span> <span class="pl-mi">0</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">--</span><span class="pl-p">)</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">d</span> <span class="pl-o">&amp;</span> <span class="pl-p">(</span><span class="pl-mi">1</span> <span class="pl-o">&lt;&lt;</span> <span class="pl-n">i</span><span class="pl-p">))</span>
            <span class="pl-n">p</span> <span class="pl-o">=</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">p</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">];</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-n">Log</span><span class="pl-p">[</span><span class="pl-n">n</span><span class="pl-p">];</span> <span class="pl-n">i</span> <span class="pl-o">&gt;=</span> <span class="pl-mi">0</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">--</span><span class="pl-p">)</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">p</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">!=</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">q</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">])</span>
            <span class="pl-n">p</span> <span class="pl-o">=</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">p</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">],</span> <span class="pl-n">q</span> <span class="pl-o">=</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">q</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">];</span>
    <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">p</span> <span class="pl-o">!=</span> <span class="pl-n">q</span><span class="pl-p">)</span>
        <span class="pl-k">return</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">p</span><span class="pl-p">][</span><span class="pl-mi">0</span><span class="pl-p">];</span>
    <span class="pl-k">return</span> <span class="pl-n">p</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">void</span> <span class="pl-nf">init</span><span class="pl-p">(){</span>
    <span class="pl-n">Log</span><span class="pl-p">[</span><span class="pl-mi">0</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span>
        <span class="pl-n">Log</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">Log</span><span class="pl-p">[</span><span class="pl-n">i</span> <span class="pl-o">&gt;&gt;</span> <span class="pl-mi">1</span><span class="pl-p">]</span> <span class="pl-o">+</span> <span class="pl-mi">1</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">j</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">j</span> <span class="pl-o">&lt;=</span> <span class="pl-n">Log</span><span class="pl-p">[</span><span class="pl-n">n</span><span class="pl-p">];</span> <span class="pl-n">j</span><span class="pl-o">++</span><span class="pl-p">)</span>
        <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span>
            <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">anc</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span> <span class="pl-o">-</span> <span class="pl-mi">1</span><span class="pl-p">]][</span><span class="pl-n">j</span> <span class="pl-o">-</span> <span class="pl-mi">1</span><span class="pl-p">];</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">(){</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">n</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">m</span><span class="pl-p">);</span>
    <span class="pl-kt">char</span> <span class="pl-n">c</span><span class="pl-p">[</span><span class="pl-mi">1</span><span class="pl-p">];</span>
    <span class="pl-kt">int</span> <span class="pl-n">x</span><span class="pl-p">,</span> <span class="pl-n">y</span><span class="pl-p">,</span> <span class="pl-n">z</span><span class="pl-p">,</span> <span class="pl-n">q</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">m</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">){</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d%d%s&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">x</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">y</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">z</span><span class="pl-p">,</span> <span class="pl-n">c</span><span class="pl-p">);</span>
        <span class="pl-n">add</span><span class="pl-p">(</span><span class="pl-n">x</span><span class="pl-p">,</span> <span class="pl-n">y</span><span class="pl-p">,</span> <span class="pl-n">z</span><span class="pl-p">);</span>
        <span class="pl-n">add</span><span class="pl-p">(</span><span class="pl-n">y</span><span class="pl-p">,</span> <span class="pl-n">x</span><span class="pl-p">,</span> <span class="pl-n">z</span><span class="pl-p">);</span>
    <span class="pl-p">}</span>
    <span class="pl-n">build</span><span class="pl-p">(</span><span class="pl-mi">1</span><span class="pl-p">);</span>
    <span class="pl-n">init</span><span class="pl-p">();</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">q</span><span class="pl-p">);</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">q</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">){</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">x</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">y</span><span class="pl-p">);</span>
        <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">,</span> <span class="pl-n">d</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">]</span> <span class="pl-o">+</span> <span class="pl-n">d</span><span class="pl-p">[</span><span class="pl-n">y</span><span class="pl-p">]</span> <span class="pl-o">-</span> <span class="pl-n">d</span><span class="pl-p">[</span><span class="pl-n">lca</span><span class="pl-p">(</span><span class="pl-n">x</span><span class="pl-p">,</span> <span class="pl-n">y</span><span class="pl-p">)]</span> <span class="pl-o">*</span> <span class="pl-mi">2</span><span class="pl-p">);</span>
    <span class="pl-p">}</span>
<span class="pl-p">}</span>
</cpde></pre></div>